Signal device.



W. THORSTEINSON.

SIGNAL DEVICE.

APPLICATION FILED JUNE 24. 1911.

Patented May 21, 1912.

-4-0 unna@ UNITED STATES PATENT OFFICE.

WALTERVTHOBSTEINSON, F WINNIPEG, MANITOBA, CANADA.

SIGNAL DEVICE.

Specification of Letters Patent.

Application filed J'une 24, 1911. Serial No. 635,052.

To all whom 'it 'may concern:

Be it known that I, XVALTER THoRsTEIN- soN, a citizen of the United' States of America, residingv at lVinnipeg, 'in the Province of Manitoba and Dominion of Canada, have invented new and useful Improvements in Signal Devices, of which the following is a specification.

This invention relates to signals and more particularly to that type of signals which are adapted to indicate extremes in heat or cold'.

The object of the invention is the provision of a'simple, efficient and thoroughly reliable signal which ma be utilized for indicating fire, or the di erent extremes in temperature which are undesirable in incubators, heating systems and the like.

Further` objects of the invention will apear as the following specific description.

1s read in connection with the accompanying drawing, which forms a part of this application, and in Which:-

Figure 1 is a diagrammatic Yview showing the system employed. Fig. 2 is an enlarged detail vertical section through the switch operating mechanism. Fig. 3 is a section on the line 3-3 of Fig. 1. Fig. 4 is a detail section on the line 4 4 of Fig. "2.

Referring more particularly to the draw ing, 1 represents an ordinary thermometer tube having a quantity of mercury or other expansive fluid therein, said tube being mounted upon a support in any suit-able manner. The upper end of the tube is open and slidably mounted within the same is a plunger rod 2 having a plunger head 3 upon its lower end adapted to rest upon the fluid within the tube 1. This plunger rod is constructed of a very fine stiff Wire so as to make the same extremely light and its opposite end from the head 3 is provided with a contacting button or head 4 formed of some suitable conducting material, preferably Which is free from magnetic qualities. Arranged adjacent the tube and projecting above the same in parallelism therewith is a slotted support 5 having suitable graduations 6 marked thereon and in the slots of Whichare adjustably secured the Contact supports 7 in the form of arms having reduced threaded extensions 8 upon which the lock4 Y nuts 9 are threaded to hold the arms in ad- Patented May 21, 1912.

formed of a conducting material' and the support 5 is preferably made of a non-conducting material. The lower arm is provided with an aperture 10 through which the plunger rod 2 is adapted to slide.

'Mounted upon the arms is one terminal 11 of an electric circuit 12 and the terminal 13 of a shunt 14. The opposite terminal of the circuit 12 is in the form lof a spring 15 connected to the plate 7 and the second terminal 16 of the shunt 14 is in the form of a spring secured to the lower plate 7. The spring terminals 1.1 and 15 andl 13 and 16 are arranged closely enough together so as to be bridged by the head 4, andare normally open so that the circuit 12 or the shunt is not complete to the battery 17 and the ringer, which are included in the main circuit 12. The opposite terminalsvof the shunt circuit from those which are mounted upon the lower plate 7 are connected in the main circuit 12 upon opposite sides of the terminals 11 and 15.

The' arms may be adjusted toward and .l

away from each other as far as is found desirable and the device is constructed to operate either from zero to 1200 or for operation at extremes of heat and cold which vary only a few, degrees. When the head 4 is in 'contact with the terminals 13 land 16 the circuit is from the battery around through thevshunt 14 across the head 4 and through t-he ringer 18 back to the battery.

This will indicate that there is either low or high temperature which, upon investigation, may be properly corrected. When the head is in contact with the terminals 11 and 15 thecircuit is entirely within the main circuit 12. The terminals 13 and 16 may be connected to a separate and independent circuit so that the attendant may know immediately whether he has to correct a high or a low temperature.

. When the device is used for a fire alarm only one of the arms and one circuit is necessary., v v

Having thus described the invention, what I claim as new is The combination with a thermometer having an open tube, of a plunger slidably mounted 1n said tube, a metallic head on said plunger, a support having an elongated s lot therein arranged adjacent said tube,

contact supporting arms adjustably secured in said slot, a pair of terminals carried by each of said arms and adapted to be bridged by said metallic head, a main circuit connected to the terminals carried by one of said arms', and a shunt circuit connected to the terminals carried by the other arm and to said main circuit. l'

In testimony vWhereofl aiix my signature in presencn of two Witnesses.

imLTER THQRSTEINSON.

Witnesses:

HEALEY H. BREWER,

H. A. BERGMAN. 

